RADIATIVE CORRECTIONS TO IN PANDAROOT A. Dbeyssi, le 17/05/2011 Radiative correction : emission of photon (soft hard and virtual) in initial and final state . PandaRoot : Generators and transport models. Effect of the PHOTOS package of PANDAROOT : Simulation with radiative correction. Monte Carlo Simulations of in PANDAROOT: Study of energy and angular distribution of electrons and positrons .

Radiative correctionS A. Dbeyssi, le 17/05/2011 Virtual and soft photon emission (Born approximation) : Hard photon emission :

RADIATIVE CORRECTIONs IN PandarooT A. Dbeyssi, le 17/05/2011 PandaRoot Framework of simulation and analysis for the PANDA experiment. Extension of FairRoot framework developped at GSI. Based on Root and Virtual Monte-Carlo (transport model : Geant3, Geant 4 and Fluka) . Event generators of PandaRoot EvtGen generator: handle complex decay channels. DPM (Dual Parton Model) generator : generation and studies of background events. UrQMD (Ultra-relativistic Quantum Molecular Dynamic Model) : used to study collision.

Radiative corrections in pandaroot A. Dbeyssi, le 17/05/2011 PHOTOS The radiative correction are implemented in Pandaratoot with the package PHOTOS : Emisson of photons as initial and final state radiation (soft and virtual photons) . Simulation with\without Photos , analysis and comparison of the obtained spectra for energy and angular distribution of the emitted particles. generation of 10 000 events. Using the Macro : run_sim-tpccombi.C EvtGen generator : EvtElectronPositron.hh. (M. GUMBERIDZE) Geant3 transport model.

Radiative corrections in pandaroot A. Dbeyssi, le 17/05/2011 Decay file (.DEC): noPhotos Decay pbarpSystem 1.0 e+ e- ElectronPositron 1; Enddecay End Proton form factor : R=1 (GE=GM). 2 values of antiproton momentum : p=1.7 and 10 GeV/c. analysis of Monte-Carlo in 4π = no detector acceptance.

Radiative corrections in pandaroot A. Dbeyssi, le 17/05/2011 noPhotos Photos

Radiative corrections in pandaroot A. Dbeyssi, le 17/05/2011 Electron-positron energy in the laboratory frame at 1.7 GeV:

Angular distribution of the electron A. Dbeyssi, le 17/05/2011 Angular distribution of the electron at 1.7 GeV : Photos noPhotos Small difference -> necessary to decrease the widh of the bin.

Probability of photon emmision A. Dbeyssi, le 17/05/2011 Probability of photon emmision in PHOTOS no γ : 75 % 1 γ : 21 % 2 γ : 4 %

Radiative corrections in pandaroot A. Dbeyssi, le 17/05/2011 Energy of emitted photons in the laboratory frame P =10 GeV/c P = 1.7 GeV/c Mostly soft photon emission

Radiative corrections in pandaroot A. Dbeyssi, le 17/05/2011 Angular distribution of emitted photons in the laboratory frame Forward emission of photons

Simulation for the channel . started Summary A. Dbeyssi, le 17/05/2011 Simulation for the channel . started First tests of the Photos have been done This work can be extended to : Tracking and reconstruction of the generated particles inside the detectors. Radiative corrections for the other reactions like the muon productions. Generator for the hard photon emission : Thank you

Radiative corrections in pandaroot A. Dbeyssi, le 17/05/2011 Positron and electron energy distribution in the centre of masse at 1.7 GeV.